Circuit breaker



Feb. 16 1926.

c. s. EPPLEY CIRCUIT BREAKER Original Filed July 27, 1923 uli mi @tbox una:

Patented Feb. 16, 1926.

PATENT OFFICE.

CHARLES S. EPPLEY, OF YORK, PENNSYLVANIA.

CIRQUIT BREAKER.

Original application filed July 27, 1923, Serial No. 654,223. Divided and this application filed March 10,

1924. Serial No. 698,231.

To all whom z5 may Concern.'

Be it known that I, CHARLES S. Errilnr, a citizen of the United States, residing at York, in the county ot .York and State of Pennsylvania, have invented certain new and useful Improvements Ain Circuit Breakers, oi which the following is a specification.

This invention relates to improvement in )ii-cuit breakers and while the circuit breaker embodying the invention lis especially designed for use in connection with the electric control panel tor automatic railway switches disclosed in my co-pending applicad tion iiled July 27th, 1923, Serial No. 654,223, of which this application is a division, the said device may be employed in various other electrical circuits.

One of the objects ot the present invintion is to provide a circuit breaker which will be positive and Iinstantaneous in its operation to break the circuit in the event of an overload being imposed thereon, so that no damage can result from the imposition of the overload because oi any sluggish action ofthe circuit breaker.

ln electrical devices of this class, an arc is very naturally formed at the moment of separation of the contacts which are normally in mutual engagement, 'and in circuit breakers heretofore designed, so iar as l am aware, no means has been provided 'lor disrupting the arc with the resuit that the contacts are liable to be burned and repairs made necessary. Therefore it is another limportant object of the present invention to provide means tor automatically disrupting and extinguishing the arc substantially at the moment it is formed, or in other words, at the moment the contacts ot the circuit breaker are separated.

ln the accompanying drawings Figure 1 is a side elevation of a circuit breaker eonstructed rin accordancewith the present invention;

Figure 2 is bottom plan view of the circuit breaker;

Figure 3 is a view in end elevation et circuit breaker.

The circuit breaker embodying the i vention comprises an insulating` base whi the nch is indicated by the numerall, and consists oi a block ot insulating material which is mounted between two side plates 2, which are of heat-resisting insulating material, and to the outer faces of which 'are secured plates 3, which support, between their upper ends, an elect-ric magnetic blowout coil indicated by the numeral d. rlhe platos 3 constitute the pole pieces of the coil 4l, and project at their lower portions below the plane of the base 1 has clearly shown in Figures 1 and 3 of the drawings, it being l that in Figure 1, one of the plates ,bserveo and the insulating piece 2, is omitted in order that other parts oi" the circuit breaker may be better illustrated. The pole pieces 3 ot' the electric magnetic coil d serve a purpose which will presently be more Afully explained. 'y A wire 5 leads from one end oi the winding coil l and is connected to one terminal Ot a resistance element (not shown) which is located in the circuit of the control panel of my said co-pendling application. The other. terminal or" the winding ot the said coil d leads to a heatingcoil which ,is indicated in general by the numeral 6 and which will presently be more speci cally describe'l. At one end the `insulating base 1 is cut away or recessed indicated by thc numeral 7, and embedded in the extended portion of the base thus provided, and indicated by the numeral 8, is a spindle 9 having` a binding nut 10 on one end Jtosecurc the lead 11 from one end ot the heating coil 3. the lead from the coil -l to the other end ot the. winding oil" the heating coil being iiidicz'ded by the numeral 12. Rotatably mounted upon the spindle S) is a circular disk 15 provided at its periphery at a.predetermined point with a notch 1li providing an abrupt shoulder indicated by the numeral 15. A short arm 16 is secured to that end o'i' the spindle opposite the end to which the binding nut 1() is applied, and a spring 1T is coiled about the spindle and secured at one end as at 18 to the disk 13 and at its other end at 19 at an opening in the arm 1G, the spring being so arranged that it has a normal tendency to rotate the dlilk 13 toward the left in Figure 1 or" the drawings, The numeral 20 indicates in general a switch blade which comprises a body leai Q1 having a right angularly upwardly turned end 22 secured in the lower side ot' the periphery ot' the disk 13 and provided at its outer or tree end with a finger button The switch blade i0 likewise comprises a more flexible and resilient leat 24 which is provided at its tree end with a contact button 25 designed to normally engage a contact 26 at the under side of the insulating base 1. A conductor wire 2T yis connected to the contact 26 and leads to the motor (not shown) ot the control panel circuit of my said co-pending application.

The coil 6 above referred to comprises a winding i8 ot' wire of a gauge such that it will not heat under normal current conditions, and this winding is arranged about a thermostatic element which is indicated in general .by the numeral 2S), and which comprises a strip 30 of a metal having a relatively low coeiicient ol expansion, and a second strip 31 having a considerably higher coeicient of expansion. These strips are both secured at one end upon the insulating base 1 by means of a bolt or other 'fastening device 32, and the strip 30 is arranged above the strip 31 and has a right angularl'y downwardly turned end 33 which normally seats within the notch 14 in the periphery of the disk 13 and constitutes an abutment for the shoulder 15. The strips are riveted .together and the free end of the strip 31 terminates directly in the angle between the strip 30 and the down turned end 33,-and under normal temperature conditions abuts at its extremity aga-instthe inner side of the abutment portion 33.

Under normal conditions, the down "turned abutment end 33 of the strip 30 of the thermostatic element will constitute an abutment for the shoulder 15, and the disk 13 will be held in the position shown in Figure 1 of the drawings, in which position it will in turn hold the switch blade 21 in a substantially horizontal position and with the contact 25 engaging the contact 26 thereby establishing a circuitthrough the circuit breaker and the electrical circuit in which it is interposed. Should an overload be imposed upon the circuit, the coil 28 will become heated and will heat the strip comprising the thermostatic element. As the strip 30 has a relatively low coetilcient of expansion and the strip 31 has a relatively high coeicient of expansion, the latter ystrip will expand to a greater degree than the strip 30, and by reason of the engagement of itsfree end against the inner side of the abutment 33, will, in expanding, deflect or distort the strip 30 suiiiciently to cause automatic disengagement of the said abutment 33 from the notch 1l thereupon the spring 517 will immediately act to rotate the vdisk 13 and thereby bring the switch blade 2O to position with its contact 25 out of engagement with the contact Q6, thus breaking the circuit. "When normal current conditions have been reestablished, the circuit breaker may be readily reset by merely pressing downwardly upon the vbutton 23 and thus iinparting rotary motion to the disk 13 until the contact 25 has been again brought into engagement with the contact 26, and the shoulder v15 has passed beneath the abutment 33 o't the strip 30 and engaged behind the same.

At the moment of separation of the contacts 25 and 26 an arc will of course be formed, but in the meantime the electric magnetic coil 5 has been energized and thc magnetic flow trom one of the poles to the other pole 3, traversing the path between the said contacts 25 and 26, will deflect the are laterally and thus disrupt and e):v tinguish the same. The insulating meansQ will preterably'be ot asbestos, although, as heretofore stated, any heat-resisting insulating material may befcmployed, and as a consequence, they will serve to protect the pole pieces 3 and prevent burning of these elements.

Having thus described the what is claimed as new is:

1. A circuit breaker comprising a base, a fixed contact thereon, a disc rotatably mounted upon the base and having a peripheral shoulder, a spring urging the disc rotatably Vin the direction in which the shoulder is presented, a thermostatic element comprising mutually united strips, one having a relatively low coetlicient of expansion and the other a relativelyhigh coefiicient of expansion, the strips .being secured at one end to the base, the free end of one strip having an angularly directed abutment engaged by the shoulder upon the disc, the free end of the other strip engaging behind the abutment of the first mentioned strip, a coil surrounding the strips invention,

and in circuit with t-he disc, and a contact comprising a blade secured between its ends tothe periphery of the disc and having a contact point at one end engaging theif'xed contact, and a tinger button upon the other end of the blade.

2. A circuit breaker comprising a base, a lined contact thereon, a spindle fixed upon the base, a disc rotatable upon the spindle and having a peripheral shoulder, a spring upon the spindle fixed at one end with relation thereto and having its other end connected to the disc andurgingfthe disc rotatably in the direction in which its shoulder is presented, a coil in circuit with the disc, a thermostatic element compris- 1 ing mutually united strips in the field of the coil and one having a relatively low coefficiente-f expansion and the other a rela tively high coetiicient of expansion, the strips being secured at one end to the base, the free end of one strip having a downwardly directed abutment engaged by the shoulder upon the disc, the free end of the other strip engaging behind the abutment of the first mentioned strip, and a Contact member comprising` a strip secured at its intermediate portion to the periphery of the dise and movable bodily with the dise and having a Contact point at one end and :L finger button et its other end, the con tact point of the member being normally in engagement with the fixed Contact.

In testimony whereof I affix my Signature.

CHARLES S. EPPLEY [L 5.] 

